1Department of biotechnology, faculty of agriculture, shahid bahonar university of kerman, kerman, Iran

2Department of biotechnology, college of agricult, Shahid Bahonar University of Kerman, Kerman, Iran

3Department of biotechnology, faculty of agriculture, shahid bahonar university of Kerman, Kerman, Iran

4Department of horticulture, faculty of agriculture, shahid bahonar university of kerman, kerman, Iran

Abstract

Sodium/proton exchangers (NHX) are key players in plant responses to salinity and have a central role in establishing ion homeostasis. NHXs can be localized in tonoplast or plasma membranes, where they exchange sodium ions for protons, resulting in the removal of ions from the cytosol into vacuole or extracellular spaces. In the present study, the expression pattern of the gene encoding Na+/H+ antiporter in the vacuolar membrane (NHX1 gene) in Leptochloa fusca (Kallar grass) was measured by a semi-quantitative RT-PCR method under different treatments of NaCl and CdCl2. Results indicated that NaCl positively affected expression levels of LfNHX1, and that the amount of LfNHX1 mRNA increased in conjunction with the rise of salinity pressure, This finding suggests that vacuolar Na+/H+ antiporter might play an important role in the salt tolerance ability of kallar grass. The results also showed that cadmium exposure significantly modulated the mRNA expression of the LfNHX1 gene, suggesting that cadmium exposure disturbed Na+ homeostasis across the tonoplast and decreased the salt tolerance ability of kallar grass.

18. Abdullah M, Akram M, Khan A, Dqureshi RH. Internal water resources management by plants under various root environment stresses with special reference to kallar grass Leptochloa fusca. In Proceedings of National Seminar on Water Resources Development and its Management in Arid Areas. 6-8 Oct 1990, Quetta, Pakistan, 145-157.